Many electronic devices, such as telecommunication devices or computing devices are provided with a number of separate foldable or pivotable subcomponents in order to easily change the appearance and/or size of a device. For example, foldable mobile phones with a clamshell configuration are very popular. Other examples are laptops and personal digital assistants (PDA), media players with or without separate displays, cameras and many more. In most of these, functional elements are present in several separate parts of the device. A main device component including a processor or similar elements may have one or more additional components foldably attached, such as a display screen or a keyboard, or e.g. a protecting cover with a signaling display. In some devices, the folding configuration may determine the current functionality of a device.
At the connecting regions or edges of two separate device parts, one or more hinges or joint elements may be provided for moving those device parts relative to each other. When data transfer is required between the separate device parts, for example in order to display data provided by the processing component, a data interconnection between those movable parts is necessary. However, due to the extensive movement and stress on these connecting joint elements during use, it is difficult to integrate a durable and reliable signal connection path into the connecting element. At the same time, the number of required signal connection paths increases with the complexity of available device functions, such as movie players with foldable high-resolution displays.
Cables and wires threaded through holes or tubes at the connecting elements may be damaged by the repeated movement and edge friction. They also limit the degrees of freedom for moving and folding the device parts with respect to each other, since e.g. a wire cannot be twisted infinitely without risking a cable break. While two-directional hinge constructions such as a folding hinge with swivel are possible with such a cable (e.g. a micro coaxial cable), this still does not allow movements in arbitrary directions, and in addition assembly of the device parts is complicated significantly. For allowing sufficient mobility, a combination of multiple hinges for several directions of movement is usually necessary. Another solution which is sometimes used in foldable or collapsible devices is to use flexible printed circuits (FPC) inside a hinge structure. FPCs may be rolled or multi-layered. Still, flexible printed circuits are subject to restrictions in flexibility due to their two-dimensional basic shape. The degree of freedom for a hinge assembled with a FPC interconnection between device parts is limited to only one direction, with a limited rotation angle.